<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>盾牌</title>
  <style>
    .wrapper{
      position: relative;
      width: 400px;
      height: 400px;
      margin: 100px auto;
      /* background-color: #ccc; */
      border-radius: 50%;
      background-image: radial-gradient(circle closest-side at center,
                      #2930ae 25%,
                      #c8143c 25%,
                      #c8143c 50%,
                      #fff 50%,
                      #fff 75%,
                      #c8143c 75%);
      box-shadow: 0 0 5px #000;
    }
    span{
      position: absolute;
      left: 50%;
      top: 50%;
      transform: translate(-50%, -50%);
      color: #fff;
      font-size: 60px;
      text-shadow: 0 0 10px #000;
    }
  </style>
</head>
<body>
  <div class="wrapper">
    <span>★</span>
  </div>
</body>
</html>